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Well the thing with the DOHC 2.5 is that the power/torque is pretty much level from 2300 rpm to 4000 rpm. So the motor doesn't produce any more or less power, the rpm relation is just a matter of speed. And more speed with a lean of the air goingin the engine works great on the highway because you can vary with traffic and retain approx same FE, but it still has too low of FE.
I'm wondering how the internals look, and if it would be possible to switch over to a different gear set. I would be concerned about making the gears too long, because the outback is pretty underpowered as an awd sedan. It might actually increase FE by going to taller gear due to the slower acceleration. Truthfully what it needs is a 5th gear. It would then be able to accelerate to shift before 2500 rpm.
I'm starting to wonder if maybe I should have just gotten a pickup truck with 4wd.
But right now it looks like i'm stuck at 25.5's for mileage. That will probably go down a bit more as the weather gets worse.
I need some more ideas to figure out how to get more economy out of the car!!!
Current ideas/projects:
-Mirrors, swapping both over to a Ford Contour mirror with a smaller cross-section. This is going to take some time, fitting the mirror has become a ***** of a project. It might be easier to find two subaru mirror bases, and mount the other mirrors to those. Currently I'm trying to convert the Ford base to the Subaru door.
-LED lights - driving in winter and on 10 hour shifts, I don't see the sun. I could reduce the load on the alternator by 6amps by swapping to led bulbs. But the cost is ~$65. Which doesn't ever have a pay back, and could be put towards another project.
-Weight reduction - currently removed spare, jack, hold downs, and trunk carpet. I don't know what else I can remove without starting to sacrifice the interior looks of the car (and potentially rendering the modifications as irreversible. I would love to try racing seats for the front, but the seats are wired into the side airbags. Removing these disables the airbag system.
-partial upper grill block. Its winter, so might be able to block off the upper grill slightly now.
-heat ducting - I thought about purchasing copper tubing and trying to draw heat from the exhaust header up to the air intake. I'm just not sure if this would work.
-switching to mobile 1, 0w-30 full synthetic - currently using a 5w-30 synthetic blend.
-air cowls on roof. Water shows the truth, the rear window does not large amount of air flowing over top. water stays in the middle of the window. some small shark fins may put air over the car instead of around the sides.
-Kammback, almost impossible on a sedan, and car would have to come out of service during the build. Which I cannot do 1) because its freakin cold 2) no other mode of transport for work commute.
-I'm tried looking for wheels, but it doesn't seem like I could feasible come up with a skinnier tire/wheel combo in a cost effective manner. I would easily drop down to a 195/205 tire from the 225, but I cannot find a rim/tire combo that could be close to cost effective and still fit. I need a minimum of a 16" wheel due to Suby brakes.
-exhaust header not sure if a boost in power would really help the FE. It might on the highway, but my commute is more stop/go and hill acceleration issues.
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